BACKGROUND: In clinical practice, laboratory results are of great importance for the diagnosis and treatment. Reference intervals of different parameters aid health-care professionals in the interpretation of results. There are very few studies on reference intervals from India. This prospective study was conducted to determine the reference intervals for platelet count (PLT) and PLT indices; mean PLT volume (MPV), PLT distribution width (PDW), and PLT large cell ratio (P-LCR).